Electromagnetic interference in the so-called radio frequency range is commonly referred to as Radio Frequency Interference (RFI). RFI can occur in a telecommunications network whose wiring is subject to strong radio frequency electrical fields. RFI is a problem in telecommunications because it impairs reception of the signal transmitted through the telecommunications network. Impairment of a transmitted signal is particularly undesirable in the transmission of voice frequency signals because of the need for a telephone subscriber to receive clear, accurate voice communications.